Key operable padlock with rotatable seal for plug

ABSTRACT

A high security padlock having a padlock casing and a generally U-shaped shackle. The casing has a central bore located between the sockets to receive and removably house a key lock plug, operable by a key slot in the bottom of the padlock body. A sealing cover member forms an upper closure for the bore above the plug and includes a pair of concave recesses which normally interfit with surface portions of the shackle legs and also includes interlock means displaced angularly from these recesses to interlock with the main body portion when either of the shackle legs are located in their associated sockets in the padlock body.

9/1932 Fitzgerald ..70/38B e I 'v Umted. States Patent 1 [111 3,710,603 Miller Jan. 16, 1973 54 KEY OPERABLE PADLOCK'WITH 2,070,012 2/1937 Jacobi ..70/38 B ROTATABLE SEAL FOR PLUG v Primary Examiner-Albert G. Craig, Jr. [75] Inventor. Harry C. Miller, Rochester, NY. y Fenwick & Lawrence [73] Assignee: Sargent & Greenleaf, Inc.,

I Rochester, NY. [57] ABSTRACT 2] Filedl p 1971 A high security padlock having a padlock casing and a 21 A N '2 184 521 generally U-shaped shackle. The casing has a central 1 0 bore located between the sockets to receive and removably house a key lock plug, operable by a key [52] U.S.Cl. ..70/38 A, 70/52 l i h bottom f th dlo k bod A sealing Cl. ..E05b v cover member forms an upper closure for the bore Field of Search R, 38 38 B, 38 C, above the plug and includes a pair of concave recesses 70/39, 52, 371 which normally interfit with surface portions of the v shackle legs and also includes interlock means dis- I References cued placed angularly from these recesses to interlock with UNITED STATES PATENTS the main body portion when either of the shackle legs are located in their associated sockets in the padlock 824,593 6/l906 Schroeder ..70/38 A body. 1,683985 9/1928 Muzzio ..70/38 B 19 Claims, 8 Drawing Figures PATENTEDJAM 16 I915 3.710.603

SHEET 2 OF 2 KEY OPERABLE PADLOCK WITH ROTATABLE SEAL FOR PLUG BACKGROUND AND OBJECTS OF THE INVENTION The present inventionrelates in general to-padlocks, and more particularly to padlocks of either the exposed shackle or shrouded shackle type, having key lock plugs and a special construction permitting removal of l facture so that it cannot be replaced without substantial destruction of the lock. However, it has been recognized that it is desirable in some instances, and particularly in connection with high security uses of padlocks,

'to provide for removal of the key lock plug'in some be substituted to permit operation of the lock by a different key. Customarily, such locks have been constructed so as to permit removal of the key plug either by use of a special change key, or by rotation of one or a pair of retaining screws accessible in the socket or sockets which normally receive the shackle legs, thus permitting change only when the lock is unlocked, or by retraction of a split ring accessible in a similar manner to operation of the retaining screw. Other key operable padlocks have been constructed wherein an exposed cover is mounted overthe bore for the key lock plug, with the cover held to the padlock body by rivets or similar fastening devices. However, such a construction does not meet the requirements of high security lock applications.

An object of the present invention is theprovision of a novel key operable padlock construction wherein the key lock plug is removable from the padlock body or case in a special manner only when the shackle has been completely removed from the case, thus permitting substitution of a key lock plug designed for a different key. i

Another object of the present invention isthe provision of a novel key operable padlock construction wherein a rotatable cover or sealing member located within the padlock body to seal the key lock plug within the body has concave segments at diametrically opposed locations designed to interfit with portions of both shackle legs of the padlock shackle so asto prevent rotation of the cover or sealing member from sealing position to release position except when'both shackle legs are removed from the padlock body.

In many uses of padlocks, the padlock is in an exposed position such that a person seeking unauthorized entry into the space secured by the padlock may attempt to saw through the shackle or insert a tool between the hasp members and the lock to wedge or chisel the lock open. A further object of the present invention, therefore, is the provision ofa novel padlock construction for improving the security of such padlocks and enhancingtheir resistance against such efforts to gain unauthorized entry. This may be accomplished by providing a shrouded type padlock body wherein a portion of the padlock body forms a shroud the present invention, a padlock of the exposed shackle type is provided with a cover adapter forming a filler block which fills the space-between the legs of the shackle, except for'a central recess portion which is sized to interfit closely with parts of two hasp end portions adjacent the shackle receiving apertures in the hasps. This adapter or filler block member effectively fills the space within the shackle to prevent insertion between the hasps and the lock of a tool for wedgingor chiseling the lock open and also makes it more difficult to saw the lock open because the saw would have to go through part of the adapter as well as the-shackle.

Other objects, advantages and capabilities of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings illustrating preferred embodiments of the invention.

' BRIEF DESCRIPTION OF THE FIGURES FIG. 1, is an exploded perspective view of an exposed shackle padlock embodying the present invention;

FIG. 2 is a vertical transverse section view thereof taken along the line 22 of FIG. 1;

FIG. 3 is'a vertical section view thereof taken along the line 3-3 of FIG. 2;

FIG. 4 is a horizontal section view taken-along the line 44 ofFIG. 3;

FIG. 5 is a horizontal section view taken along the line 5-5 of FIG. 2;

FIG. 6 is a bottom view of the locking bolt;

FIG. 7 is a perspective view of the cover adapter having a shackle filler'blocki which may be employed with the padlock; and

FIG. 8 is a perspective view of a shrouded type padlock embodying the present invention, with the shackle shown exploded therefrom.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS character 10, which is of the exposed shackle type. The

padlock 10 comprises a padlock body 11 of generally elliptical configuration in top plan view, having a top surface l2 and a bottom surface 13. The padlock body 11 is preferably a unitary casted body, formed for example of hardened steel, and has a pair of closed bottom sockets or bores 14, 15 opening through the top about the shackle whichdenies direct access 'to the surface 12 for receiving the legs of the shackle 16. The sockets l4, 15 have slightly constricted entrance por tions 14a, 15a of cylindrical configuration defining downwardly facing transition surfaces or shoulders 14b, 15b, spaced below the top surface 12.

The shackle 16 is preferably in the form of a U- shaped rod of hardened steel having alonger leg 17 and a shorter leg 18. The longer leg 17 passes through the rotatable movement relative'to the padlock body 11,

but is normally restrained against withdrawal from the socket 14 by means of a pin 19 driven through an opening 11a in the padlock body into a pin aperture 17b in the leg 17. An end of the pin 19 projects slightly from a side of the leg 17 into the socket 14 below the shoulder 14b in underlapping relation to the shoulder so that the shoulder 14b will intercept the projecting end of the pin upon upward movement of the shackle. The free end portion of the shorter leg 18 enters through the circular entrance opening 150 in the top surface 12 into the closed bottom socket 15 in the padlock body, when the shackle is in locking position. By this construction, the shorter leg 18 of the shackle can be withdrawn from the padlock body 11 when the padlock is unlocked, and can be swung to an exposed position by rotating the shackle 16 about the axis of its longer leg 17, the abutment of the ends of pin 15 with shoulder 14b defining the limit of this withdrawal movement. The U-shaped shackle 16 also comprises the usual curved inter mediate portion extending between the legs 17 and 18, which serves as the portion which engages the usual apertured hasps member or pair of hasps members, as indicated at 21a and 21b, having apertures 22a and 22b which are of a diameter closely approximating the diameter of the shackle and are adapted to register with each other to receive the shackle therethrough. The shackle legs 17 and 18 each have a notch 17a, 180 located within the padlock body when the shackle is in locking position as the portion which engages the usual apertured hasps member or pair of hasps members, as indicated at 21a and 21b, having apertures 22a and 22b which are of a diameter closely approximating the diameter of the shackle and are adapted to register with each other to receive the shackle therethrough. The

shackle legs 17 and 18 each have a notch 17a, 18a

located within the padlock body when the shackle is in locking position and which are disposed in the confronting or inwardly facing portions of the shackle legs to receive nose portions of a rotatable locking bolt 24 as later described.

The padlock body includes a closed bottom lower central bore portion 25 which communicates with the sockets l4 and 15 and is shaped and sized to snugly accommodate a key lock plug 26 of conventional construction, having a usual rotatable cylinder therein, including a bolt actuator 26a, disposed at the upper end of the plug 26 when the core is properly arranged in the padlock body. The core of plug 26 also includes a key opening in the downwardly facing end portion of the rotatable cylinder, indicated at 26b in FIG. 2, located immediately above a key opening 27 in the bottom surface 13 of the padlock body for insertion of the key into the key opening of the plug cylinder and rotation of the key through the appropriate arc to unlock the key lock. Since the conventional key lock plug 26.usually has a pair of flat sides, indicated at 26c, and a pair of concave arcuate ends, the central bore 25 for the plug is either similarly shaped in horizontal cross-section or is cylindrical over most of its height and has flats at its upper end to embrace-and hold the plug, as will appear from FIG. 5.

Immediately above the lower central bore 25 is an enlarged upper central bore portion 28 of cylindrical configuration having a larger radius than the curved portions of the lower central bore portion 25, for accommodating the rotatable locking bolt 24 and a rotatable closure seal or cover 29 of generally cylindrical configuration. The rotatable locking bolt 24, as will be apparent from FIGS. 1, 2 and 6, has a downwardly extending boss formation 24a which is recessed to define a downwardly facing socket or well 24b having a radial extension and shaped to properly interfit with the bolt actuator 26a of the key lock plug so as to be rotated by the cylinder of the plug 26 when the latter is shifted to unlocking position by the proper key. The locking bolt 24 also includes a pair of diametrically oppositely. projecting nose portions 240 and 24d which interfit into the notches 17a, 18a of the shackle legs 17,

9 18 when the key lock plug cylinder, and therefore the locking bolt 24, are in locking position. Suitable arcuate recesses 30 extend radially outwardly in the walls of the upper bore 28 at the level of the locking bolt 24 to accommodate rotary arcuate movement of the locking bolt nose portions 24c, 24d from the locking position to the unlocking position to free the shackle 16 for withdrawal to its unlocking position.

The closure seal or cover member 29 fits downwardly over the locking bolt 24 into the upper bore portion 28, in a manner similar to a manhole cover. The closure seal 29 includes a cylindrical top portion 29a which is of the same radius as the upper bore portion 28 and intercepts a portion of the sockets or bores 14, 15 for the shackle legs. The cylindrical periphery 29b of the cylindrical top portion 29a has a pair of diametrically opposed concave interruptions 290 which complement the sockets l4 and 15 so that the surfaces of the concave interruptions 29c'form a continuation of and complete the cylindrical walls defining the entrance portions of the sockets l4 and 15. Extending downwardly from the circular top portion 29a are a pair of locking lug formations 29d having downwardly facing bottom surface portions which bear upon the shelf or shoulder surfaces, indicated at 2811, defining the bottom of the upper bore portion 28 to locate the top surface of the cylindrical top portion 29a flush with the top surface 12 of the padlock body. The locking lug formations 29d also include outwardly projecting lugs 29d extending beyond the cylindrical periphery 29b to interfit into arcuate recesses 31 in portions of the cylindrical surface bounding the upper bore portion 28 immediately adjoining the sockets 14, 15 in an angular direction in which the locking bolt is rotated during movement to unlocking position.

Before the shackle has been assembled in the padlock body, the key lock plug 26 is inserted into the lower central bore 25 therefor, after which the locking bolt 24 is fitted downwardly on the bolt actuator portion 260 of the plug. The closure seal 29 is then in-' stalled in the padlock body by lowering the same downwardly into the upper bore portion 28 with the lugs 29d disposed in the sockets l4, 15 for the shackle legs, until the lugs 29d bottom on the shelf or shoulder recess 24a, whereupon the closure seal is rotated in a clockwise direction as viewed in FIGS. 4 and 5 to project the lugs 29d into the recesses 31 and aline the concave interruptions 290 in the periphery 29b of the closure seal with the sockets 14, 15 so that they register with and form continuations of these sockets. With the key lock in unlocked condition, wherein the nose portions 24c, 24d of the locking bolt 24 are withdrawn from the sockets l4, 15, the shackle legs 17 and 18 can be inserted into the sockets l4, 15 until the longer leg l7 bottoms in its socket l4, and the pin 19 is then driven into the shackle aperture 17b to restrain the shackle in the padlock body. The presence of the longer leg 17 in its socket 14 in both the locking and unlocking positions of the shackle prevents any rotation of the closure seal 29 from its sealing or closed position because the shackle leg 17 is interfitted in the concave interruptions 29c of the closure seal which forms part of the socket l4. v

In order to remove the key lock core or plug and replace it with another core or plug for use with a different key, the pin 19 must be driven into aperture 17b in shackle leg 17, so that the shackle 16 can be completely Withdrawn from the padlock body. The closure seal 29 can then be rotated to a position registering the lugs 29d with the sockets 14 and and the closure seal withdrawn from the padlock body. With the padlock body inverted, the locking bolt 24 and key lock plug 26 are withdrawn from the bore portions 25 and 28, and another key lock plug 26 may then be inserted into the lower central bore 25. The locking bolt 24 is then reassembled onto the bolt actuator 26a of the new plug, and the closure seal 29 is inserted and inter locked in the padlock body in the same manner as in the initial installation, after which the shackle 16 can be reinserted in the sockets 14 and 15 and a new retaining pin 19 installed.

A modified version of the cover member is shown in FIG. 7, wherein a filler block is combined with the cover member and is indicated at 36. The member 36 includes a lower body portion 36a having a cylindrical periphery and a pair of diametrically opposed concave interruptions, described later which complete the cylindrical walls defining the entrance portions 14a and 15a of the sockets. Extending downwardly from the lower body portion 36a are a pair of locking lug formations 36d having downwardly facing bottom surface portions to engage the shelf or shoulder surfaces defining the bottom of the upper bore portion 28, so as to properly locate the lower body portion 36a in the padlock body.

The locking lug formations 36d also include outwardly projecting lugs 36d which extend beyond the periphery of the body portion 36a to interfit into the arcuate recesses 31 in the padlock body immediately adjoining the sockets 14, 15.

Extending upwardly from, and integrally formed with the lower body portion 36a is a filler block portion 37a of generally cylindrical configuration in its lower region, for example of the same diameter as portion 36a,

It will be apparent that the presence of the filler block portion 37a and 37b filling the region between the shackle legs 17, 18 when the shackle is in closed position will form an additional barrier which provides a much greater amount of material which must be sawed through if one attempts to make a saw cut through the shackle to gain unauthorized access to the enclosure secured by the lock and the close nesting relation of the adapter 35 with the hasps portions in its recess 37c makes it more difficult to insert a wedging tool between the hasps and lock to wedge or chisel the lock open.

Still further protection is afforded by providing a shrouded padlock body as illustrated at 40 in FIG. 8, wherein the body includes a shroud portion 41 extending above the normal level of the padlock body provided with a generally cross-shaped recess 42 for receiving the shackle therein so that the top of the curved portion of the shackle can be located level with or immediately below the level of the top surface 43 of the shrouded portion of the padlock body. The

. hasps portions 21a, 21b to be secured by the shackle 16 terminating in a somewhat dome-shaped upper portion 1 21a, 21b which lie below the shackle openings 22a,

22b. The diametrically opposite surfaces of the tiller block portion 37a along the diametric axis which parallels the plane of the shackle 16 is provided with a pair of concave recesses 37d sized to interfit with the con frontingshackle portions and nestingly receive the adjacent portions of the shackle to thereby fill all of the region lying between the shackle legs 17, 18 and below the curved top portion 20 of' the U-shaped shackle 16 other than those portions filled by the lower hasps sections.

may be introduced through the rearwardly opening portion 44 of the recess. The construction of the shrouded padlock is otherwise the same internally as the padlock construction of the embodiment of FIGS. 1 to 6, except that the pin 19 is omitted so that the shackle can be wholly withdrawn from the padlock body when the locking bolt 24 is in unlocking position. If desired, the two shackle legs may be the same length in this embodiment. In the embodiment illustrated, the front wall of the shrouded type padlock body 40 is provided with a central recess 45 for receiving the end of a chain, indicated at 46, and is provided with' a pair of small flanking recesses 47, together with drilled openings 48 extending between the recesses 47 and int-ersecting the upper portion of the recess 45 to receive a drive pin therethrough to be driven through the drilled openings 48 and a link of the chain 46 for coupling the padlock body 40 to'the door or other security closure by means of the chain.

What is claimed is:

l. A padlock comprising a padlock casing having a bottom wall portion, a main body portion, and an upper body portion, a U-shaped shackle including a curved intermediate portion and a pair of shackle legs, said casing having laterally spaced sockets opening through said upper body portion for receiving the shackle legs and accommodating axial reciprocative movement of the shackle between a lower locking position and an upper release position, said main body portion having a central bore therein located between said sockets shaped to receive and removably house a key lock plug, a key lock plug removably received in said bore including bolt means movable into and out of locking engagement with said shackle legs, said bottom wall portion defining the bottom of said'bore and having va key opening therein for projection of a key into said key lock portion of slightly greater diameter than the spacing between the confronting surfaces of said shackle legs and having 'a pair of diametrically opposite concave recesses inthe perimeter of said top portion registering with and forming a portion of said sockets to receive confronting portions of the shackle legs therein at a selected angular position of said cover member, said cover member also including interlock means displaced angularly from said concave recesses to interlock with said main body portion when said concave recesses register with said sockets in positions for receiving said shackle legs for retaining said cover member against withdrawal from the padlock casing when the shackle is in said lower locking position.

2. A padlock as defined in claim 1, wherein said key lock plug includes a bolt operator projecting upwardly therefrom, and said bolt means comprises a removable locking bolt member releasibly coupled to said bolt operator.

3. A padlock as defined in claim 2, wherein said interlock means includes lug formations projecting downwardly and outwardly from said cylindrical top portion of said cover member and said main body portion having internal arcuate lug recesses concentrically bounding said bore and communicating with said sockets, the outwardly projecting portions of said lug formations being movable downwardly in said sockets when the shackle legs are withdrawn therefrom and being angularly shifted into said arcuate lug recesses to interlock the cover member in said bore and aline the concave recesses with said sockets.

4. A padlock as defined in claim 3, wherein the upper body portion of said padlock casing includes a shroud formation extending upwardly from said main body portion to a top surface substantially at the level of the uppermost portion of the shackle when the shackle is in locking position, said shroud formation having a cruciform recess extending downwardly from said top surface defining a first slot elongated along the plane of the shackle for wholly receiving the shackle in nested relation therein and defining a second slot perpendicularly intersecting the first slot and opening rearwardly through said upper body portion to receive a pair of apertured hasp members therein in position for insertion of the shackle through the apertures thereof.

5. A padlock as defined in claim 2, wherein said padlock casing has a flat top wall surface through which said sockets open, said shackle projecting from said top wall surface and having one leg thereof slidably retained in said casing by removable means, and said top portion of said cover member having a flat substantially circular top surface located flush with said top wall surface when the cover member is interlocked with said main body portion.

6. A padlock as defined in claim 2, adapted for use with a pair of apertured hasp members disposed in abutting registered relation having apertures for receiving the padlock shackle, the padlock including a filler block formation including a cylindrical body portion and a spherical dome-shaped upper portion, each filler block portion having diametrically opposite concave recess channels therein to receive confronting surface portions of the shackle legs and adjacent portions of the curved intermediate portion nested therein, the filler block formation substantially filling the space between said shackle legs and having a diametrically extending recess across the upper portion thereof along an axis perpendicular to the plane of the shackle sized to snugly accommodate portions of said hasp members directly below the shackle apertures therein.

the shackle for wholly receiving the shackle in nested relation therein and defining a second slot perpendicularly intersecting the first slot and opening rearwardly through said upper body portion to receive a pair of apertured hasp members therein in position for insertion of the shackle through the apertures thereof.

8. A padlock as defined in claim 1, wherein said padlock casing has a flat top wall surface through which said sockets open, said shackle projecting from said top wall surface and having one leg thereof slidably retained in said casing by removable means, and said top portion of said cover member having a flat substantially circular top surface located flush with said top wall surface when the cover member is interlocked with said main body portion.

9. A padlock as defined in claim 1, wherein said key lock plug includes a bolt operator projecting upwardly therefrom, and said bolt means comprises a removable locking bolt member releasibly coupled to said bolt operator for angular movement about a vertical axis having end portions projecting into said sockets within said main body portion at a locking position thereof, and said shackle legs having confronting notches receiving said end portions of said locking bolt when the latter occupies said locking position.

10. A padlock as defined in claim 9, wherein said interlock means includes lug formations projecting downwardly and outwardly from said cylindrical top portion of said cover member and said main body portion having internal arcuate lug recesses concentrically bounding said bore and communicating with said sockets, the outwardly projecting portions of said lug formations being movable downwardly in said sockets when the shackle legs are withdrawn therefrom and being angularly shifted into said arcuate lug recesses to interlock the cover member in said bore and aline the concave recesses with said sockets.

11. A padlock as defined in claim 10, wherein said padlock casing has a flat top wall surface through which said sockets open, said shackle projecting from said top wall surface and having one leg thereof slidably retained in said casing by removable means, and said top portion of said cover member having a flat substantially circular top surface located flush with said top wall surface when the cover member is interlocked with said main body portion by interfitting of said lug formations in said arcuate lug recesses.

12. A padlock as defined in claim 10, adapted for use with a pair of apertured hasp members disposed in abutting registered relation having apertures for receiving the padlock shackle, the padlock including a filler block formation including a cylindrical body portion and a spherical dome-shaped upper portion, each filler block portion having diametrically opposite concave recess channels therein to receive confronting surface portions of the shackle legs and adjacent portions of the curved intermediate portion nested therein, the

filler block formation substantially filling the space between said shackle legs and having a diametrically extending recess across the upper portion thereof along an axis perpendicular to the plane of the shackle sized to snugly accommodate portions of said hasp members directly below the shackle apertures therein.

13. A padlock as defined in claim 10, wherein the upper body portion of said padlock casing includes a shroud formation extending upwardly from said main body portion'to a top surface substantially at the level of the uppermost portion of, the shackle when the shackle is in locking position, said shroud formation having a cruciform recess extending downwardly from said top surfacedefining a first slot elongated along the plane of the shackle for wholly receiving the shackle in nested relation therein and defining a second slot perpendicularly intersecting the first slot and opening rearwardly through said upper body portion to receive a pair of apertured hasp members, therein in position for insertion of the shackle through the apertures thereof.

14. A padlock as defined in claim 1, adapted for use with a pair of apertured hasp members disposed in abutting registered relation having apertures for receiving the padlock shackle, the padlock including a filler block formation including a cylindrical body portion and a spherical dome-shaped upper portion, each filler block portion having diametrically opposite concave recess channels therein to receive confronting surface portions of the shackle legs and adjacent portions of the curved intermediate portion nested therein, the filler block formation substantially filling the space between said shackle legs and having a diametrically extending recess across the upper portion thereof along an axis perpendicular to the plane of the shackle sized to snugly accommodate portions of said hasp members directly below the shackle apertures therein.

15. A padlock as defined in claim 1, wherein said interlock means includes lug formations projecting downwardly and outwardly from said cylindrical top portion of said cover member and said main body portion having internal arcuate lug recesses concentrically bounding said bore and communicating with said sockets, the outwardly projecting portions of said lug formations being movable downwardly in said sockets when 'theshackle legs are withdrawn therefrom and being angularly shifted into said arcuate lug recesses to interlock the cover member in said bore and aline the concave recesses with said sockets.

l6. A padlock as defined in claim 15, wherein said padlock casing has a flat top wall surface through which said sockets open, said shackle projectingfrom.

said top wall surface and having one'leg thereof slidably retained in said casing by removable means, and said top portion of said cover member having a flat substantially circular top surface located flush with said top wall surface when the cover member is interlocked with said main body portion by interfitting of said lug formations in said arcuate lug recesses.

17. A padlock as defined in claim 15 adapted for use with a pair of apertured hasp members disposed in abutting registered relation having apertures for receiving the padlock shackle, the padlock including a filler block formation including a cylindrical body portion and a spherical dome-shaped upper portion, each filler block portion having diametrically op osite concave recess channels therein to receive con rontmg surface portions of the shackle legs and adjacent portions of the curved intermediate portion nested therein, the

filler block formation substantially filling the space between said shackle legs and having a diametrically extending recess across the upper portion thereof along an axis perpendicular to the plane of the shackle sized Y to snugly accommodate portions of said hasp members directly below the shackle apertures therein.

18. A padlock as defined in claim 15, wherein the upper body portion of said padlock casing includes a shroud formation extending upwardly from said main body portion to a top surface substantially at the level of the uppermost portion of the shackle when the shackle is in locking position, said shroud formation having a cruciform recess extending downwardly from said top surface defining a first slot elongated along the plane of the shackle for wholly receiving the shackle in nested relation therein and defining a second slot perpendicularly intersecting the first slot and opening rearwardly through said upper body portion to receive a pair of apertured hasp members therein in position for insertion of the shackle through the apertures thereof.

19. A padlock as defined in claim 1, wherein the upper body portion of said padlock casing includes a shroud formation extending upwardly from said main body portion to a top surface substantially at the level of the uppermost portion of the shackle when the shackle is in locking position, said shroud formation having a cruciform recess extending downwardly from said top surface defining a first slot elongated along the plane of the shackle for wholly receiving the shackle in nested relation therein and defining a second slot perpendicularly intersecting the first slot and opening rearwardly through said upper body portion-to receive a pair of apertured hasp members therein in position for insertion of the shackle through the apertures thereof. 

1. A padlock comprising a padlock casing having a bottom wall portion, a main body portion, and an upper body portion, a Ushaped shackle including a curved intermediate portion and a pair of shackle legs, said casing having laterally spaced sockets opening through said upper body portion for receiving the shackle legs and accommodating axial reciprocative movement of the shackle between a lower locking position and an upper release position, said main body portion having a central bore therein located between said sockets shaped to receive and removably house a key lock plug, a key lock plug removably received in said bore including bolt means movable into and out of locking engagement with said shackle legs, said bottom wall portion defining the bottom of said bore and having a key opening therein for projection of a key into said key lock plug for operating the latter, a sealing cover member forming an upper closure for said bore above said plug, said sealing cover member including a cylindrical top portion of slightly greater diameter than the spacing between the confronting surfaces of said shackle legs and having a pair of diametrically opposite concave recesses in the perimeter of said top portion registering with and forming a portion of said sockets to receive confronting portions of the shackle legs therein at a selected angular position of said cover member, said cover member also including interlock means displaced angularly from said concave recesses to interlock with said main body portion when said concave recesses register with said sockets in positions for receiving said shackle legs for retaining said cover member against withdrawal from the padlock casing when the shackle is in said lower locking position.
 2. A padlock as defined in claim 1, wherein said key lock plug includes a bolt operator projecting upwardly therefrom, and said bolt means comprises a removable locking bolt member releasibly coupled to said bolt operator.
 3. A padlock as defined in claim 2, wherein said interlock means includes lug formations projecting downwardly and outwardly from said cylindrical top portion of said cover member and said main body portion having internal arcuate lug recesses concentrically bounding said bore and communicating with said sockets, the outwardly projecting portions of said lug formations being movable downwardly in said sockets when the shackle legs are withdrawn therefrom and being angularly shifted into said arcuate lug recesses to interlock the cover member in said bore and aline the concave recesses with said sockets.
 4. A padlock as defined in claim 3, wherein the upper body portion of said padlock casing includes a shroud formation extending upwardly from said main body portion to a top surface substantially at the level of the uppermost portion of the shackle when the shackle is in locking position, said shroud formation having a cruciform recess extending downwardly from said top surface defining a first slot elongated along the plane of the shackle for wholly receiving the shackle in nested relation therein and defining a second slot perpendicularly intersecting the first slot and opening rearwardly through said upper body portion to receive a pair of apertured hasp members therein in position for insertion of the shackle through the apertures thereof.
 5. A padlock as defined in claim 2, wherein said padlock casing has a flat top wall surface through which said sockets open, said shackle projecting from said top wall surface and having onE leg thereof slidably retained in said casing by removable means, and said top portion of said cover member having a flat substantially circular top surface located flush with said top wall surface when the cover member is interlocked with said main body portion.
 6. A padlock as defined in claim 2, adapted for use with a pair of apertured hasp members disposed in abutting registered relation having apertures for receiving the padlock shackle, the padlock including a filler block formation including a cylindrical body portion and a spherical dome-shaped upper portion, each filler block portion having diametrically opposite concave recess channels therein to receive confronting surface portions of the shackle legs and adjacent portions of the curved intermediate portion nested therein, the filler block formation substantially filling the space between said shackle legs and having a diametrically extending recess across the upper portion thereof along an axis perpendicular to the plane of the shackle sized to snugly accommodate portions of said hasp members directly below the shackle apertures therein.
 7. A padlock as defined in claim 2, wherein the upper body portion of said padlock casing includes a shroud formation extending upwardly from said main body portion to a top surface substantially at the level of the uppermost portion of the shackle when the shackle is in locking position, said shroud formation having a cruciform recess extending downwardly from said top surface defining a first slot elongated along the plane of the shackle for wholly receiving the shackle in nested relation therein and defining a second slot perpendicularly intersecting the first slot and opening rearwardly through said upper body portion to receive a pair of apertured hasp members therein in position for insertion of the shackle through the apertures thereof.
 8. A padlock as defined in claim 1, wherein said padlock casing has a flat top wall surface through which said sockets open, said shackle projecting from said top wall surface and having one leg thereof slidably retained in said casing by removable means, and said top portion of said cover member having a flat substantially circular top surface located flush with said top wall surface when the cover member is interlocked with said main body portion.
 9. A padlock as defined in claim 1, wherein said key lock plug includes a bolt operator projecting upwardly therefrom, and said bolt means comprises a removable locking bolt member releasibly coupled to said bolt operator for angular movement about a vertical axis having end portions projecting into said sockets within said main body portion at a locking position thereof, and said shackle legs having confronting notches receiving said end portions of said locking bolt when the latter occupies said locking position.
 10. A padlock as defined in claim 9, wherein said interlock means includes lug formations projecting downwardly and outwardly from said cylindrical top portion of said cover member and said main body portion having internal arcuate lug recesses concentrically bounding said bore and communicating with said sockets, the outwardly projecting portions of said lug formations being movable downwardly in said sockets when the shackle legs are withdrawn therefrom and being angularly shifted into said arcuate lug recesses to interlock the cover member in said bore and aline the concave recesses with said sockets.
 11. A padlock as defined in claim 10, wherein said padlock casing has a flat top wall surface through which said sockets open, said shackle projecting from said top wall surface and having one leg thereof slidably retained in said casing by removable means, and said top portion of said cover member having a flat substantially circular top surface located flush with said top wall surface when the cover member is interlocked with said main body portion by interfitting of said lug formations in said arcuate lug recesses.
 12. A padlock as defined in claim 10, adapted for use with a pair of apertured hasp members disposed in abutting registered relation having apertures for receiving the padlock shackle, the padlock including a filler block formation including a cylindrical body portion and a spherical dome-shaped upper portion, each filler block portion having diametrically opposite concave recess channels therein to receive confronting surface portions of the shackle legs and adjacent portions of the curved intermediate portion nested therein, the filler block formation substantially filling the space between said shackle legs and having a diametrically extending recess across the upper portion thereof along an axis perpendicular to the plane of the shackle sized to snugly accommodate portions of said hasp members directly below the shackle apertures therein.
 13. A padlock as defined in claim 10, wherein the upper body portion of said padlock casing includes a shroud formation extending upwardly from said main body portion to a top surface substantially at the level of the uppermost portion of the shackle when the shackle is in locking position, said shroud formation having a cruciform recess extending downwardly from said top surface defining a first slot elongated along the plane of the shackle for wholly receiving the shackle in nested relation therein and defining a second slot perpendicularly intersecting the first slot and opening rearwardly through said upper body portion to receive a pair of apertured hasp members therein in position for insertion of the shackle through the apertures thereof.
 14. A padlock as defined in claim 1, adapted for use with a pair of apertured hasp members disposed in abutting registered relation having apertures for receiving the padlock shackle, the padlock including a filler block formation including a cylindrical body portion and a spherical dome-shaped upper portion, each filler block portion having diametrically opposite concave recess channels therein to receive confronting surface portions of the shackle legs and adjacent portions of the curved intermediate portion nested therein, the filler block formation substantially filling the space between said shackle legs and having a diametrically extending recess across the upper portion thereof along an axis perpendicular to the plane of the shackle sized to snugly accommodate portions of said hasp members directly below the shackle apertures therein.
 15. A padlock as defined in claim 1, wherein said interlock means includes lug formations projecting downwardly and outwardly from said cylindrical top portion of said cover member and said main body portion having internal arcuate lug recesses concentrically bounding said bore and communicating with said sockets, the outwardly projecting portions of said lug formations being movable downwardly in said sockets when the shackle legs are withdrawn therefrom and being angularly shifted into said arcuate lug recesses to interlock the cover member in said bore and aline the concave recesses with said sockets.
 16. A padlock as defined in claim 15, wherein said padlock casing has a flat top wall surface through which said sockets open, said shackle projecting from said top wall surface and having one leg thereof slidably retained in said casing by removable means, and said top portion of said cover member having a flat substantially circular top surface located flush with said top wall surface when the cover member is interlocked with said main body portion by interfitting of said lug formations in said arcuate lug recesses.
 17. A padlock as defined in claim 15, adapted for use with a pair of apertured hasp members disposed in abutting registered relation having apertures for receiving the padlock shackle, the padlock including a filler block formation including a cylindrical body portion and a spherical dome-shaped upper portion, each filler block portion having diametrically opposite concave recess channels therein to receive confronting surface portions of the shackle legs and adjacent portions of The curved intermediate portion nested therein, the filler block formation substantially filling the space between said shackle legs and having a diametrically extending recess across the upper portion thereof along an axis perpendicular to the plane of the shackle sized to snugly accommodate portions of said hasp members directly below the shackle apertures therein.
 18. A padlock as defined in claim 15, wherein the upper body portion of said padlock casing includes a shroud formation extending upwardly from said main body portion to a top surface substantially at the level of the uppermost portion of the shackle when the shackle is in locking position, said shroud formation having a cruciform recess extending downwardly from said top surface defining a first slot elongated along the plane of the shackle for wholly receiving the shackle in nested relation therein and defining a second slot perpendicularly intersecting the first slot and opening rearwardly through said upper body portion to receive a pair of apertured hasp members therein in position for insertion of the shackle through the apertures thereof.
 19. A padlock as defined in claim 1, wherein the upper body portion of said padlock casing includes a shroud formation extending upwardly from said main body portion to a top surface substantially at the level of the uppermost portion of the shackle when the shackle is in locking position, said shroud formation having a cruciform recess extending downwardly from said top surface defining a first slot elongated along the plane of the shackle for wholly receiving the shackle in nested relation therein and defining a second slot perpendicularly intersecting the first slot and opening rearwardly through said upper body portion to receive a pair of apertured hasp members therein in position for insertion of the shackle through the apertures thereof. 